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Home >> Chevy Truck >> 2012 >> Equinox AWD L4-2.4L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0481

P0481




DTC P0480, P0481, P0691, P0692, P0693, or P0694 (LEA)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0480
- Cooling Fan Relay 1 Control Circuit

DTC P0481
- Cooling Fan Relay 2 Control Circuit

DTC P0691
- Cooling Fan Relay 1 Control Circuit Low Voltage

DTC P0692
- Cooling Fan Relay 1 Control Circuit High Voltage

DTC P0693
- Cooling Fan Relay 2 Control Circuit Low Voltage

DTC P0694
- Cooling Fan Relay 2 Control Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

The engine cooling fan system is composed of one cooling fan, 2 relays, the engine control module (ECM), and the associated wiring. The cooling fan assembly includes 1 resistor mounted in the cooling fan shroud. This combination of components enables the ECM to operate the cooling fan at 2 speeds using two fan control circuits. The ECM activates the applicable relay by grounding the control circuit with a solid state device called a driver. Each driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage. The ECM will operate the cooling fan at either Low or High speed based on the cooling requirements.

Conditions for Running the DTC

* The ignition voltage is greater than 11 volts.

* The ECM driver transitions from ON to OFF or from OFF to ON.

* DTC P0480, P0481, P0691, P0692, P0693, and P0694 run continuously when the conditions above are met.

Conditions for Setting the DTC

The commanded state of the ECM driver and the actual state of the control circuit do not match for greater than 5 seconds.

Action Taken When the DTC Sets

DTCs P0480, P0481, P0691, P0692, P0693, and P0694 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0480, P0481, P0691, P0692, P0693, and P0694 are Type B DTCs.

Diagnostic Aids

* The ECM has the capability of providing command to the fan relays even when a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.

* The scan tool cooling fan output control operates as follows:

- Cooling Fan Relay 1 operates the fan at low speed

- Cooling Fan Relay 2 operates the fan at a high speed

* When disconnecting or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the correct orientation in the fuse block. Test the mating electrical terminals for tightness.

Reference Information

Schematic Reference

Engine Cooling Schematics [1][2]Cooling System

Connector End View Reference

* Component Connector End Views Sunshade - Left Front

* Electrical Center Identification Views Fuse Block - Underhood Label

Description and Operation

Cooling Fan Description and Operation (3.0L) Cooling Fan (3.0L)Cooling Fan Description and Operation (2.4L) Cooling Fan (2.4L)

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

1. Ignition ON, command the appropriate Cooling Fan Relay ON and OFF with a scan tool. You should hear the relay click when commanded ON and OFF.

2. Engine operating, observe the DTC information with a scan tool. DTC P0480, P0481, P0691, P0692, P0693, or P0694 should not set.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect both of the KR20 cooling fan relays.

Note: The following test must be performed on both fan relay circuits.

2. Ignition ON, verify that a test lamp illuminates between ground and the relay coil ignition circuit terminal listed below:

* KR20C cooling fan low speed relay terminal 86

* KR20D cooling fan high speed relay terminal 86

• If the test lamp does not illuminate, test the relay coil ignition circuit for or an open/high resistance.

Note: The following tests must be performed on both fan relay control circuits.

3. Connect the red lead of the DMM to a control circuit terminal listed below. Connect the black lead to ground. Set the DMM on the diode setting. The DMM should display OL:

* KR20C cooling fan low speed relay terminal 85

* KR20D cooling fan high speed relay terminal 85

• If less than the specified range, test the appropriate relay coil control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.

Note: The following tests must be performed on both fan relay control circuits.

4. Command the cooling fan relay ON and OFF with a scan tool. The DMM should transition from OL when commanded OFF to less than 1 V when commanded ON.

• If the circuit voltage does not correspond to the specified values, test the control circuit for an open/high resistance or a short to voltage. If the circuit tests normal, replace the K20 engine control module.

5. If all circuits test normal, test or replace the appropriate KR20 relay.

Component Testing

1. Ignition OFF, disconnect the KR20 cooling fan relay.

2. Test for 70-110 ohms between terminals 85 and 86.

• If not within the specified range, replace the KR20 cooling fan relay.

3. Measure the resistance between the terminals listed below. The DMM should display OL:

* 30 and 86

* 30 and 87

* 30 and 85

* 85 and 87

• If less than the specified range, replace the KR20 cooling fan relay.

4. Connect a 20 A fused jumper wire between relay terminal 85 and B+. Connect a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

• If greater than the specified range, replace the KR20 cooling fan relay.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)

* Control Module References Programming and Relearning for ECM replacement, setup, and programming

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